In your tank, I would want 2 Koralia #1's or one Koralia #3 or a #1 and a #2. This would give you about 20 time s turnover rate not counting the return flow.

The return flow does count towards overall flow to a point but is limited to depth which means you could have a lot of flow in the top of the tank but might not translate to the bottom. What pump are you using in your sump for return?

The Rio 1400 has a 0 head pressure rating of 420 gallons per hour. Figuring you will be pushing up about 4 feet up to the main tank, you will end up with about 230-260gph. Most any hang on overflow should handle 600gph drainage.

If you want to maximize flow through the sump and take advantage of the return flow back into the display, I would suggest at least a Mag drive 7 or 9.5 for a return pump. A Mag 7 will pump 700gph at 0 head, Mag 9.5 950gph at 0 head pressure etc. I use a Mag 12 on my 75g tank and it just keeps up with my overflow.

Most reef ready tanks in the 72-90 gallon range will use a Mag 9.5 pump as a return pump.

The 1700 should be fine for the return. You should be fine with a Koralia 2 or 3 along with the return flow.

I am a koralia fan as well. Wide water outspread just like seios. great design.

very good. i like the idea of the flow being spread out rather than a jet ...seems like it would be more natural

....how long should I cycle this live rock before i can add it to my tank? - - just a regular cycle?until tests are all clear?